Vent structure



NOV. 5, w GROTHE VENT STRUCTURE Filed Sept. '7, 1937 INVENTOR. Wa/er rahe BY M y v, ha@

A TTORNE Y.

Patented Nov. 1940 UNITED azzeszs veur s'mnc'runa walter eroine, .i1-mea., onu., amor a, ont.

rpilln- Tractor Oo.. San Leandro, poration of California Calif., a cor- Appueauon september 7, 1937 serial N.y1sz ,ss4

f. 4 claims. (o1. zzo- 44) My invention relates to fuel tanks employed in carrying a supply of fuel for use in internal com-- bustion engines, and such other tanks as require ventingto the atmosphere; and more particujo larly relates to a vent structure for such tanks.

In the operation of internal combustion engines, clean fuel`is a necessity. This is of particularimportance when the internal combustion engine is of the compression ignition type, due to l the fact that mechanism, such as fuel injection pumps and valves, embodied in the fuel injection system of such engines, must be manufactured to exceedingly `close toleranc in the order of hundred thousandths and millionths of an inch to obtain proper operation of the engine. Dirty fuel gaining access to such precisely tted parts may result in seriously impairing the proper functioning of the mechanism and possibly result in inJury thereto. It has accordingly been the practiceto incorporate in the fuel line to the fuel injection sys- .tem, means in the form of lter units for sep` larating out from the fuel, al1 dirt and other material which might injure the pump and valve mechanism or otherwise deleteriously affect the operation of the engine. As the lter units become more and more impaired in their operation due to the presence of deleterious material in the interstices thereof, which has been separated out vfrom the fuel, it becomes necessary to either clean these units or replace them with new ones. Since the frequency with which these units must be cleaned or replaced depends in large measure upon the amount of deleterious material or matter filtered out from the fuel, it becomes desirable to keep the fuel in the fuel tank, free of contamination other than what may already be present in the fuel whenplaced in the tank, and this, normally is quite low, as it is common practice to introduce linto the tank only fuel which has previously been ltered. Thus, by minimizing contamination of the fuel subsequent, to its introduction into the tank, the load on the lter mechanism is maintained low, and the frequency with which it becomes necessary to clean the filter units is reduced. The useful life of a lter is .furthermore increased thereby. Fuel tanks, in general are normally provided with a vent to the atmosphere, to maintain at- 0 mospheric pressure within the tank and to per-- mit breathing induced by sloshing of the fuel in the tank and in response to changes in the tank capacity and fuel volume as affected by changes in temperature. In many constructions, the 5 vent is incorporated in the cap which serves as a closure for the filling opening in -the'tank. In

prior constructions, such cap in many instances was provided with a horizontal baille or similar construction to inhibit slopping of the fuel through the vent opening, but such was not ade- 5 quate protection or safeguard against entrance of dust to the tank; and apparently the fact that 4the tankvent might constitute a possible source of fuel contamination, did not receive much consideration. Investigations to determine the exl0 tent to which fuel might become contaminated through the vent of the supply tank, indicate it to be quite appreciable; suicient in fact to damage the fuel injection equipment of an engine Vafter a few months service; were it not for the 15 presence ofthe fuel filters with which such engines are provided.

It is accordingly an object of my invention to provide an improved ventv structure for a fuel tank which shall embody improved: 4 20 (1) Means to permit eiilclent iiow of ,air into the fuel tank, to the exclusion oi.' dust or other matter present in the air;

(2) Long tortuous passageway for the incoming air within a relatively small space; 25 (3) Arrangement for ltering material which may be readily removed for cleaning or replacement;

(4) Means to prevent return ow into the tank of such fuel as may splash out and accumulate 30 in the ller cap; and

(5) Mechanism that can be easily manufactured and assembled.

Additional objects of my invention will be brought out in the following description of my 35 improved ller cap taken in connection with the f accompanying drawing wherein:

Fig. l is a top plan view of the cap mounted on a tank, Aonly a. portion of the top wall of which tank is Shown. 40

Fig. v2 is a vertical section taken along the line 2-2 of Fig. 1.

Fig. 3 is a bottom view of the cap only, taken along the line 3 3 of Fig. 2. Y

Fig. 4 is a horizontal section through the cap 45 taken in planes indicated by the line l-I of Fig.

2, .to expose the inside arrangement of the bailles withinthe cap.

The above views are substantially to scale.

In general my invention contemplates the4 pro- 50 vision of `means which will enable power venting and breathing to take place in connection with the use of fuel tanks, and at the same time emciently inhibit the entrance into the tanks of deleterious matter which might contaminate the portions of the tortuous passageway or path excharacteristics, and which is preferably filled or packed with filtering material to cooperate in screening `out undesirable deleterious matter tending to ilow or drift into the tank.

The convolved tortuous passage is most economically and conveniently formed by a nested arrangement of baiiles within the filler cap. the

tending through the bames having their lower edges progressively at higher levels as the path recedes from the vent opening in the cap, the purpose of this elevational relationship being twofold. Firstly, dust or other deleterious matter entering the vent hole will have to follow the equivalent of a continually rising spiral path, against the force of gravity, before it could gain entrance to the fuel tank. This fact coupled with the presence of4 the ltering material in the tortuous path. very effectively removes the dust content from the incoming air.

The other advantage contemplated by the ele -v vational rise in the baille openings pertains to preventing a return flow back into the tank, of such oil as may splash out from the tank into the tortuous passage in the filler cap. Such 011,'

should the accumulation become' sufllclent to overflow the intermediate bales, will ow out through the vent opening and carry with it some of the sediment which may have previouslyfsettled out in the filtering material and at the bot tom of the cap. In this respect, the cap construction may be looked upon as a self 'cleaning device. In no case. can the filtered out dust be washed into the tank by such oil as may accumulate within the cap, since the baille opening which connects with the internal chamber of thetank is at a higher level than any of the other openings.

Discussing the invention in greater detail and with reference to the accompanying drawing, the cap comprises an outer shell l, substantially circular in form, with suitable finger grips 2 integrallyformed thereon. The shell is provided with an internally threaded depending skirt portion 3 of enlarged diameter for attachment to a tank 5. This .construction results in the formation of a shoulder 1 adjacent-the lower end of the smaller diameter portion 9 of the cap to receive in clamping engagement therewith, a sealing` means for closing the bottom opening to the cap. The portion of the depending skirt adjacent the aforementioned shoulder 1 is undercut to constitute an inner circumferential groove |5 for a purpose hereinafter described.

Depending from the roof of thecap and formed integrally therewith, as by casting or otherwise, are plurality of nested cylindrical bailles I1, I9, respectively, concentrlcally arranged with respect to the center of the cap and extending downwardly to a plane Just slightly above the plane of the above mentioned shoulder 1.

The cap is vented to the atmosphere by means of an opening 2| therethrough preferably at a point close to the skirt portion 3, and the baille |1 of largest diameter which is the one closest to the wall ofthe cap is provided adjacent the roof of the cap with a passageway or opening 23 therethrough at a point farthest removed from the 'aforementioned vent opening 2|. 'I'he lower edge therethrough, butJ aty a point farthest removed from the opening 23 through the rst baille |1, and in this baille |9 the passageway is also located adjacent the roof of the cap.

This baille I9 of smaller diameter is internally threaded to receive'a stud 21 of a length suiicient to extend from a' point substantially below the plane of the shoulder 1 for the reception of a clamping nu-t and vsuitable washers, to a point above the level of the lower edge of the opening 23 through the larger diameter baille |1. The stud 21 has an axial passage 29 therethrough to form a tube whereby it effects a connection with the opening'25 through the baille I 9 to which it is threaded. The passage 29 is constricted at its lower end at 29 to minimize escape of liquid therethrough from the tank. .Tube 21 actually constitutes a portion of the last mentioned baille I9 and may be considered as such, and when so considered, it will be noted that the vent opening 2| and the openings 23 and 25 through the various baffles |1 and |9- have their lower edges at successively. higher levels.

The arrangement and construction of the bafribbon for example, or screening wound or other wise formed into annular shapes to t the spaces between batlies, may be employed to fill these spaces.

The bottom of the cap is closed by sealing means which may be of a composite type comprising a layer of cork 33 or other satisfactory sealing material applied around the tube21, and retained in sealing engagement with the lower edges of the bailles and the shoulder 1 by means of a backing plate 35 of similar size but of stiffer material, such as molded plastic, metal, or the like and a nut 31 threaded upon the lower end of tube 21; with a washer 39 positioned between the nut and the backing 35. A lock washer 4| may conveniently be used to maintain the nut 31 in position on the tube 21.

`The fact that the bailles |1 and I9 do not quite extend to the plane of the shoulder 1 insures a leak-proof flt of the sealing means against the lower edges of bailles I1 and 9, and shoulder 1 because this enables the backing plate to be stretched under tension when nut 31 is tightened to hold sealing layer 33 tightly against the parts in question. A similar t could be assured, even were the bailles extended to the plane of the shoulder 1, by slightly dishing the sealing means or utilizing a vthicker layer 33 of the sealing material. It is thus seen that the sealing means is clamped with sull'licent pressure to eect a dust and liquid tight seal for the vent structure to prevent leakage of fuel, air or dirt in either direction. A loose iltting gasket 43 of suitable material such as chrome leather, or the like, is sprung into the aforementioned groove I5, and is adapted to be clamped against a filler spout or tube 45 upon application of the cap to the tank 5. to preclude leakage of fluid from the tank at this point.

, In the drawing, I have illustrated my improved ller cap mounted on the fuel tank 5, wherein the filler tube or spout 45 is in the form of an externally threaded plus preferably welded to the' upper wall of the tank and having a depending channeled portion 41 for receiving a level gauge .49, which gauge may include a length of stiff wire dlsl having a right angie portion u for supporting,

it from the filler plug 45. Theflller plug is re-v cessed to form a shoulder 55 from which to hang a screen 51, .the screen being affixed to a depending sleeve A59 having a circumferential flange 6I A 1 0. adapted to rest upon the shoulder 55 of the plug and be retained in position by a circular spring clip 83 adapted tobe sprung into a groove formed in the wall of the recessed portion of the plug adjacent the aforementioned shoulder 55.

l5 From .the preceding description, it will be noted that the bailles are concentrically arranged without partitions therebetween, thus providing a simple construction to fabricate. Inasmuch as the baiiies are preferably concentrically arranged without partitions therebetween, the fluid entering vent 2I will, as previously mentioned, have a divided flow through the vent structure along two paths or courses. The various openings 2I, 23 and 25 in the concentric walls are preferably 5 located so that each opening is at a point farthest removed from the similar opening in an adjacent wall or baille, to cause the two courses along which the fluid flows, to be of equal length.

AHence, a like or balanced settling of deleterious matter will occur in each of the paths. Openings 2|, 23 and 25 need not be arranged in the manner described. However, any other arrange; ment would provide paths of unequal length, and this might result in insuflicient settling of deieterious matter in the shortest path. If desired, only one long tortuous path for flow of fluid may be provided, for example, by rearrangement of the openings and positioning partitions between the bailles, but this would increase the cost of manufacture. g

Each path, as previously stated, denes the equivalent of a rising spiral This, of course, means that deleterious matter carried by the incoming air will have to travel the long tortuous paths against the force of gravity in order to gain entrance to the tank. It is unlikely that such deleterious matter will follow through a long tortuous or Winding ascending path unless propelled by a stili current of air, which of course is never present in a vented ller cap.

It is further to be noted that the portions of the rising paths lying between the bailles are of considerably greater cross sectional area than the portions of the paths which pass through the 53 baiiies. The effect of this is to considerably reduce the air velocity between baffles, and thereby permit the force of gravity to exercise a greater influence upon the deleterious matter in the air, in the matter oi separating it out therefrom.

6H When once settled out below openings 2|, 2'3 and 25, the deleterious matter will pass beyond the inuence of subsequent fluid flow because of the traps for such deleterious matter, which are provided-by the portions of the baiiles below such 05 openings. It is not as if the path were defined by a tube or pipe, in which case such deleterious matter as might settle out in the tube would remain in a position to be urged forward with each new movement of air through the vent.

7" The likelihood of deleterious matter successfully traversing the upwardly winding path formed by the bailiing is additionally precluded by the presence of the packing or filtering material positioned within the long tortuous paths formed 75 by the bailles. The incoming air thus becomes thoroughly freed from thedust or other delete- -be attached. A 5

Where thefuel tank 5 forms part of the fuel, system of an automotive or self propelled vehicle.4 considerable `sloshing around of the 'fuel in the tank occurs. particularly when such vehicle is a tractor, operating over roughor hilly terrain: i0 and a small amount of such fuel is apt to splash A through the passage 29 of the tube 21 and settle in the cap betweenthe two innermost bames I1 and I8. This, if anything. adds to the advam i tages of thecap construction, as a means for re- 15 moving deleterious matter from the incoming air, as the fuel will wet the ltering material 3| and thus enable it to function'more eectively as a filter means, by causing the deleterious mat r to adhere thereto. 20

The construction of the baming within the cap, precludes a return flow of such fuel as may' gainentrance to the cap through the orice 29'-, Should an appreciable amount of fuel accumulate between the two innermost baies I1 and I9, 25 it is apparent that it will spill through the outermost of these two battles by reason of the fact that the lower edge of the opening or passage 23 through such baille is purposely located at a lower level than the upper end of the passage 29 30 Y through tube 21-fwhich is considered as part of the innermost bathe I9. Ultimately, such fuel will run through the vent-opening 2| to the atmosphere, carrying with it some of the dust or other material which has previously settled out in the 35 cap, Thus the flow of such fuel as may become trapped in the cap, will be in a direction away from the orifice 28 and toward the outside of the cap through the vent opening 2I. This is a matter of some importance, when it is noted that 40 such fuel will become saturated with deleterious matter inthe cap and every precaution should be exercised .to keep it from getting back into the tank.

From the preceding description of my improved 45 filler cap, it will be apparent that the device may be very readily manufactured and assembled and just as easily disassembled when it is found necessary or desirable to either clean or replace the ller or packing material. 50

While I have described one specific embodiment of my invention, it is apparent that it is susceptible to variations within the scope of mechanical skill and without departing from the scope of my invention. The number of bailles, for example, may be varied as well as the arrangement thereof just so long as the advantages attributed to my invention will appear in the modified construction. The bailies need not be integrally formed with the cap but may be separately fabriso cated and retained in position in the cap by the sealing means II for example. And furthermore, in so far as my invention is concerned, the venting structure may be incorporated in a wall of the tank, independently of the filler cap, in e5 which case the filler cap should be constructed to provide an air-tight closure for the filler tube or opening.

My invention is not limited in its application to tanks for the holding of fuel, nor is it limited eign filtrable material which may be present in the gas.

I. accordingly. do not desire to be limited in. my protection to the specific details described nor the specinc applications mentioned except as may be necessitated by the prior art and the Y appended claims. I

I, therefore, claim as my invention:

1. A cap i'or a, fuel tank or the like formedto provide an air path therethrough from the outside atmosphere to within the tank, a plurality ofssubstantially concentrically arranged bailies in said cap and extending substantially the depth thereof, openings through said baiiies located so that an opening through one baille is farthest removed from an opening through an adjacent barile to provide a convolved path for iiow of air.

2. A vent structure for a fuel tank or the like, having a chamber, a vent in a side wall of said chamber, a passage for communication with said tank, and a plurality of bailles between said passage and said vent arranged one within another and extending from tthe mot of and substantially the depth of said chamber, each of said bailies having an opening therein and the positions of said openings being at increasingly higher levels starting from adjacent said vent.

3. A vent structure for a fuel tank or the like,

having a chamber, a vent in a side wall of said chamber adjacent the bottom thereof, 'a passage extending substantially the depth of said chamber.`each of said bailies having anopening, the

outermost baille having its opening disposedf'at a pointsubstantially farthest removed from and above said vent. and the openings in adjacent baiiles being so located that an opening in one baille insubstantially farthest removed from an opening in an adjacent baille with an opening in an inner baille above that in the adjacent outer bame, whereby a plurality of ascending con- -volved paths are provided for now oi iiuid beopening disposed at a point substantially "far-- thest removed from and above said vent, and the openings in adjacent baiiles being so located that an opening in one baille is substantially farthest removed from an opening in an adjacent baille with the opening in an inner baille above that in the adjacent outer baille, whereby a plurality of ascending convolved paths are provided tor Sage.

WALTER GROTHE.

CERTIFICATE oF CORRECTION. Patent No. 2,220,528. November 5, 191m.

wALTER GROTHE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, second column, 4line 5l, for the word "power" read --proper-; page 2, first column, line ,59, before plurality insert -a-; page 5, second column, line 55, after the word "run" insert --out--g and that the said Letters Patent should be read with this correction therein that the same may con- Aform to the record of the case in the Patent Office.

Signed and sealed this 17th day of December, A. D. 19LLO.

Henry van Arsdale,

(Seal) Acting Commissioner of Patents. 

